[Elecraft] DATA A mode and WSJT-X

[Bill Frantz]

A quick guess. The DSP bandwidth for Data A is separate than 
from USB. Try adjusting the HI and LOW cut knobs on your radio. 
(I'm assuming a K3 or KX3.) I have used my K3 for digital modes, 
JT, PSK  etc. using WSJT-X, cocoaModem, and fldigi. There's a 
bit of a learning curve with all these programs, but it isn't 
too steep, and it's a computer after all. :-)

73 Bill AE6JV

On 1/23/15 at 8:51 PM, edouard at lafargue.name (Edouard Lafargue) wrote:

>I tried JT65 for the first time today (there is a first for everything,
>right?), and to my surprise, I discovered that for some reason, the DATA
>mode is not usable on that program!
>
>Not 100% sure the mailing-list allows images in emails, so I will try to
>describe the issue as clearly as possible:
>
>- In USB mode, with a flat EQ, I get a flat spectrum apart from the
>actual JT9/JT65 chirps, from 200Hz to 3000 Hz
>- In DATA A mode, on the other hand, I get a peak around 100Hz, nothing
>until 300Hz, then a huge noise peak raising from 300Hz, peaking at 500hz
>and going slowly down to 1kHz. Then a big dip in signal/noise centered
>around 2kHz. In other words, very distorted signal!
>
>Image speaks for itself: http://imgur.com/QyqpzEh
>
>I am pretty sure this does not come from the radio, with a simple
>audio waterfall displaying at the same time in another program I don't see
>this artifact, but I wonder if anyone else has seen this and can explain
>it? Could it be an FFT artifact linked to the sampling rate of the
>soundcard and an internal sampling rate of the radio in DATA mode?
>Something else ??
>
>Kind of scratching my head on this one, maybe smarter/more experience
>Hams on the list will have an answer!
>
>Oh yes: WSJT-X is running on a Mac, not that it should really matter.
>
>73 de Ed, W6ELA
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